Monday, 30 April 2007

Critter Spot: Rock Spider...

Collecting rocks (aka mineral specimens) means that sometimes you also acquire livestock...

This was one of those times. I put a mineral specimen under my microscope and found this little critter weaving a tiny web across a small cavity on the rock's surface. Its body is only about 1mm long and I have no idea what species...

Saturday, 28 April 2007

Meaning of Life Spot: Recycling Nutrients...

The circle of life - things are born, grow, die, and are recycled in some other form... In my early years, I was taught that you can't destroy energy. You simply transform it into another form.

So it is with nature. Fungi like this one are sprouting up beneath the Silver Birch trees at the back of our house. Autumn is past the half-way mark and Winter is beckoning...

My meaning of life? Look at everything every day.

Wednesday, 25 April 2007

Mineral Spot: Stolzite, Kara Mine...

Last Friday, members of the North West Tasmania Mineral Group headed off to the Kara Mine. These have been regular trips to date, however a change in management may mean that future trips are in doubt.

Stolzite, a rare lead tungstate, has been found here on a few occasions, but never in the abundance and quality of this trip. A full report will be included in the next issue of the Australian and New Zealand Mineral Collector magazine.

Tuesday, 24 April 2007

Art Spot: Easy Rider...

My effort in the WatercolorWorkshop April Project - Wild Birds!

Can't get much wilder than this!

Mineral Spot: Kyanite...

Kyanite is an aluminium silicate with an unusual property - it has a different hardness depending on which direction you scratch it. It is generally blue in colour and occurs as prismatic crystals.

It is found in aluminium-rich regional metamorphic rocks such as mica-schists and gneisses. In Australia, the best-known locations where it can be found are in the Harts Ranges in the Northern Territory (where the one pictured is from) and from near Broken Hill in New South Wales. It can also be found in a number of other locations in Australia and New Zealand.

Monday, 23 April 2007

Art Spot: The Lucky Fossickers...

Wanted to do another painting with a bit of humour in it...and this is the result, the Lucky Fossickers.

Lucky coz they've found some nice crystals, and 'lucky' with the flies!

Friday, 20 April 2007

Sun Spot: Hampshire, Tasmania...

Waiting at the alloted meeting place for today's field trip to the Kara Mine, I took this photo of the early morning sun. The location is the Natone turnoff at Hampshire, north west Tasmania. There was a bit of smoke in the air from burning-off operations which I think added to the shot...

Tuesday, 17 April 2007

Mineral Spot: Opalised Belemnites...

Belemnites are an extinct group of cephalopods, similar to the modern squid. Their fossilised remains are usually restricted to their shell. Rarely, as in the photo, the fossils are opalised. This specimen was in one of the showcases at Tucson and is probably from Coober Pedy in South Australia.

Saturday, 14 April 2007

Mineral Spot: Death of a mineral specimen...

The image left is a closeup of a lovely pyrite balls on calcite from Broken Hill, New South Wales. However, there is something sinister happening. Have a close look at the circled area in the second image. The grey area is also pyrite, but it has what is sometimes known as 'pyrite disease'. That is, the pyrite is breaking down and causing the whole specimen to slowly disintegrate. If left with other sulphide minerals, they too will likely break down.

Barry Flannery describes the process in a Mindat forum thus: "They turn into ferrous sulphate then ferric sulphate and sulphuric acid. The acid accelerates the reaction, so it becomes autocatalytic, with the result that once it gets started it speeds up and there's no stopping it. As the reaction products have a larger volume than the starting material the whole specimen just disintegrates and ends up as a handful of crumbs. Meanwhile the acid generated eats through everything around it."

Thursday, 12 April 2007

Mineral Spot: Gibbsite on Crocoite...

'OK, what's this?' you might ask. A cow's udder? A fungus?

None of the above. Its a photo of the mineral gibbsite, an aluminium hydroxide, coating orange crocoite crystals. Often, mineral dealers try to remove this coating but this often dulls the crocoite crystal lustre. I personally like the association, especially when the specimen looks a bit 'wierd'...

Wednesday, 11 April 2007

Critter Spot: Jumping Spider...

Have you ever heard the song about the redback on the toilet seat? No? Well never mind. You can find out about via this Google search...

Anyway, this is a shot of a different spider, a jumping spider, not on our toilet seat, but in the same room. These guys are quite cute :o)

Mineral Spot: Tasmanian Pyromorphite...

...and while we are on the subject of hexagonal minerals...this is a photo of nicely colour-zoned pyromorphite crystals from the Platt Prospect, Dundas, western Tasmania. The field of view is about 2mm.

Art Spot: Beryl...

No, its not a portrait, but a pencil drawing of a beryl crystal. I did this sketch one evening when I was interstate for work, as well as a calcite sketch.

Beryl is better known as one of the gem forms. These include emerald (green), aquamarine (blue), morganite (pink) and heliodor (golden yellow). It is quite hard, which is why it is used for jewelry, and forms hexagonal prisms as can be seen in the drawing.

In Australia, one of the best known localities for beryl is the Triple Chance Mine, near Broken Hill, New South Wales. The metal beryllium was extracted from beryl from this location and used in the Apollo spacecrafts. Not gem-quality material though!

Monday, 9 April 2007

Critter Spot: Brown Tree Frog...

This is a photo of a Brown Tree Frog (Litoria ewingi) found today at the first collecting location, a Cambrian basalt quarry near Maydena. It is a common and widespread species that grows to about 4.5cm.

So why, if it called a tree frog, was it found under a rock in the middle of the quarry floor, a long way away from the nearest tree?

Sun Spot: Styx River Area, Tasmania...

The Mineralogical Society of Tasmania held a field trip in the Maydena area today. Three locations were visited. This is a view looking back towards the third one, a quartz locality. Nothing like the Styx River that separates the world of the living from the world of the dead! Although, after a hard day of breaking rocks (and falling over a few times!), I feel a bit like the latter...

Could not have asked for better weather. Fine, sunny, and a warm 25 degrees C. Not bad for mid-Autumn.

Saturday, 7 April 2007

Sky Spot: Big Sky in Tasmania...

Big skies are not all that common in Tasmania because of all of the hills and mountains. It is said that if you flattened out the whole State, it would be as big as Australia. This photo was taken in the Northern Midlands while I was on my way back from a field collecting trip, and I now use it as a banner on my website.

Mineral Spot: Chalcedony 'Fingers'...

Chalcedony is a cryptocrystalline form of quartz.

Normally, true blue mineral collectors would not have such specimens in their collection. However, once in a while, a specimen such as this turns up. Its like something out of a cartoon (ever noticed that cartoon characters only have three fingers and a thumb?).

This specimen of chalcedony comes from a cavity in basalt at Springsure in Queensland. Chalcedony was first reported from here in 1887.

Wednesday, 4 April 2007

Critter Spot: Green Iridescent Fly...

These flies were out and about during January this year, and make excellent close-up subjects. I haven't seen any around for some time now. Must not like the cooler weather.

Their bodies exhibit iridescence, similar to some other flies and beetles. They are very attractive critters (as far as flies go!).

Incidentally, there are differences of opinion as to what constitutes macro versus close-up photography. I choose to call my shots macro regardless of whether they are technically macro or close-up primarily coz I am using the macro function of my camera.

Tuesday, 3 April 2007

Sun Spot: Echuca...

Spent the weekend at Echuca in northern Victoria with friends of ours, and fellow mineral enthusiasts, Keith and Margaret Brown. They live on what was once a dairy property.

The weather was superb with the temperature in the low 20 degrees C (the photo was taken early morning, about 6:30am looking towards the East).

Keith and Margaret have to move soon into a retirement village and I have been helping them to work out what to do with their large mineral collection.